Finishing tool

ABSTRACT

An abrasive tool employed for the grinding, polishing, and surface finishing of metal, plastic, rubber and other fabricating materials. The device is particularly adapted for a quick mount to or release from a power driven head of chuck-like form. Embodiments are characterized by an adapter shaft to which is slip fit a flat molded disposable head providing a free flexing planar operating face surfaced with an abrasive material. The head is light in weight and formed of molded plastic to have projected to the rear of said operating face and integral therewith means for a slip friction fit thereof to the adapter shaft.

II v r! I II a D United States Patent [151 3,683,567 Ali 1 Aug. 15, 1972 [54] FINISHING TOOL 3,136,100 6/1964 Robertson... ..,....5l/378 Inventor: F. li Pascal Drive 3, MaCKay et al in-.5 Pratt 8t m 3,395,417 8/1968 Matouka ..5l/358 [22] Filed: Dec. 24, 1969 3,468,079 9/1969 Kaufman 51/378 [21] Appl Primary Examiner-Donald 0. Kelly Attorney-Jerome P. Bloom [52] US. Cl ..51/358 [51] Int. Cl. ..B24b 23/02, 824d 13/ 14 [57] ABSTRACT [58] meld Search 2 5 5 3 An abrasive tool employed for the grinding, polishing, v and surface finishing of metal, plastic, rubber and other fabricating materials. The device is particularly [56] References Cited adapted for a quick mount to or release from a power UNITED STATES PATENT driven head of chuck-like form. Embodiments are characterized by an adapter shaft to which is slip fit a 3,520,090 7/ i970 Lee..., ..5l/358 flat molded disposable head providing a free flexing 3,270,467 9/1 B|0k "51/358 planar operating face surfaced with an abrasive 3,526,065 9/1970 Lee ..5l/358 material. The head is light i weight d f d of 2,379,984 7/1945 Nereaux ..287/ 103 A molded plastic to have projected to the rear of said 2,453,222 1 H1948 Hammontree ..5l/377 operating face and integral therewith means for a Slip 472,823 4/1892 Ross ..5 11358 friction fit h f to the adapter h ft 2,385,249 9/l945 Albertson ..5l/377 3,082,582 3/1963 Jeske ..5 U358 13 Claims, 4 Drawing Figures "III, I

Patented Aug. 15, 1972 3,683,567

FIG-4 INVENTOR FRANK F. A L l ATTORNEY FINISHING TOOL THE IN VENTION The present invention is directed to a new and improved abrasive surfaced finishing tool which is more economical to fabricate and more efficient and satisfactory in use. It is a highly advantageous replacement for conventional abrasive disk assemblies and disc mounting applicators.

BACKGROUND OF THE INVENTION tion the down time for removing and replacing the ad-. 1

hesive paper has assumed critical proportions, from the standpoint of efficiency as well as economy. In efforts to solve this problem, particularly as to the use of the abrasive paper in disc form, there have been introduced semi-rigid adapters professed to ease the replacement and cost problems above noted. Such an adapter is noted in the U.S. Patent to A. Field, US. Pat. No. 3,307,300 dated Mar. 7, 1967. However such have not solved the existing problems to any great extent. Their application requires time and manipulation, particularly since they require a screw fitting. Moreover, they are not that inexpensive as to significantly reduce the cost involved.

, DESCRIPTION OF A PREFERRED EMBODIMENT The present invention obviates the above problems from the standpoint of both cost and efficiency. It provides an abrasive tool unit comprised of minimal parts of an inexpensive nature, one which is more simply applied by the machine operator and one which enables its abrasive surface to function more effectively for a longer period of time than would normally be anticipated.

A preferred embodiment comprises a shaft-like key forming a quick release adapter which can be slip fit and simply chucked to apower driven head. Completing the invention tool is a head of molded plastic presenting a flat disc form, from the center and rear face of which is projected a portion which slip fits to the key element and, with a slight fractional twist, is friction locked thereto. The opposite or operating face of the disc is planar and has fixed coextensively thereto means providing it with an abrasive surface. Due to the nature of the plastic disc being thin and free flexing and the abrasive surface applied in a manner and form to flex therewith, the device of the invention is endowed with greater durability and versatility of application than previously possible using rigid and semi-rigid backing devices.

A primary object of the invention is to provide a surface grinding, polishing or finishing tool which is more economical to fabricate, more efficient and satisfactory in use and unlikely to damage articles to which the same is applied.

Another object of the invention is to provide an improved finishing tool which can be more quickly applied and replaced.

A further object of the invention is to provide a sanding or like device which affords a free flexible abrasive surface which is more versatile in application.

An additional object of the invention is to provide a unique adapter head affording an improved disposable finishing tool having a ready capability of a slip fit and quickly keyed mount to a driving head.

Another object of the invention is to provide an improved finishing tool and unique head therefor possessing the advantageous structural features, the inherent meritorious characteristics and means and mode of use herein described.

With the above and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation as hereinafter described or illustrated in the accompanying drawings,

thereof to its keyed adapter shaft.

Like parts are indicated by similar characters of reference throughout the several views.

As seen in the drawings, the invention unit as illustrated consists of three parts. It includes the shaft-like key 10, an adapter head 11,- and a thin abrasively surfaced disc 12 of sheet-like thickness.

The key '10 comprises to one end thereof a shaft portion 14 of uniform diameter and pin-like form which can be slip fit to a chuck provided on the conventional driving head of any powered shaft. The remote end of the key 10 has the form of a stub shaft portion 16 of a diameter equal to that of the shaft portion 14. The portion 16 has a diametral aperture accommodating the projection therethrough and the press fit thereto of a short key pin 17. The latter projects equally from diametrally opposite sides of the key but to a lesser radial extent than an adjacent relatively expanded intermediate section 18 of the key. The latter is knurled and enlarged and so positioned to facilitate the handling of the key to slip fit the shaft portion 14 to a chuck or to couple the key to the adapter head 11 in a manner soon to become obvious.

The adapter head 11 is molded of a simple light weight plastic. It provides the form of a thin flexible sheet-like disc 19 presenting a planar operating surface 20. The latter has a central cavity 21 defined by an offset 22 of cup-like form. The peripheral wall of the cup is cylindrical in shape while its base 23 has a diametral slot 24 intersected by a small central aperture 25. The diameter of aperture 25 is just large enough to accommodate the slip fit projection therethrough of the stub shaft portion 16 of key 10 and the opening provided by slot 24 just wide and long enough to accommodate the slip fit therethrough of the pin 17. At its inner surface, to either side of slot 24, the base of cup 22 is molded to a ramp form designated in FIGS. 1 and 4 by numerals 26 and 27. The respective diametrally opposite remote ends of ramps 26 and 27 present the low and the high portions of the ramps. Thus the low of one ramp is immediately opposite the high of the other. As will be seen, the ramps serve as co-operative camming surfaces.

Accordingly, it will be readily apparent that the adapter 11 may be grasped in the hand and, with slot 24 aligned with and centered in reference to stub shaft 16 and key pin 17, slip fit over the same to have the base of cup 22 bottom on the shoulder 28 provided to the one end of the enlarged portion 18 of the key immediately adjacent the pin 17. The spacing between pin 17 and shoulder 28 is such that on a bare fractional rotation of the adapter head 11 the projected ends of the pin are cammed by and ride up a short way on the remote ends of ramps 26 and 27 to frictionally lock the adapter to the key. A quick fractional counter-rotation disengages the parts 10 and 11. The ease in the procedure is self-apparent in use. 7

Note the back surface of disc 19 includes, molded thereon about cup 22, a network of radial spoke-like hemi-cylindrical protuberances 29 terminating just short of its periphery and intersected at their ends by a circular hemi-cylindrical protuberance 30.

As shown the disc 12 is adhesively attached. However, abrasive particles may be directly applied to surface and permanently adhered thereto in accordance with the invention concepts.

As should be obvious from the foregoing, the adapter 11 provides for the permanent and direct bonding thereto of the abrasive particles at its planar operating face 20. Moreover, as integrated, in any case or manner, such particles become part of a self-sustaining but free flexing thin plastic disc which is stabilized, resilient and self conforming to the contours of the workpiece to which it is applied by virtue of its own structured form. There is an absence of the layered construction of the prior art which could render absent the flexing capabilities inherent in the embodiment of the present invention. Moreover, the adapter 11 is free of special fasteners which could complicate fabrication or render difficult or time consuming the mount of the adapter.

The device of the invention is thus easy to fabricate, has a simple unique fast mount and accordingly reduces cost and down time in replacement to a minimum. Moreover, the simple flexing capability of the simple structure of the thin abrasive surfaced adapter 1] enables full use of the abrasive with minimal wear characteristics as compared to devices for similar application in the prior art. The polishing capabilities are optimal since the loading of the workpiece in use of the invention devices is minimal. The cost of the invention embodiments is thus minimal, the plastic content in the forming of adapter 11 being very small. Thus the invention does provide a device to obviate the problems of the prior art.

From the above description it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise but one of several modes of putting the invention into effect and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the appended claims.

Having thus described my invention, 1 claim:

1. A device for use in surface grinding, polishing and like operations comprising a thin flexing adapter having on one face a substantially planar operating surface for receiving abrasive means as a cover and, as an integral part of its opposite face, means to mount to a drive medium with a slip friction fit, and a drive medium in the form of a shaft device having at one end a pin-like form for slip fit to a chuck-like driving head and at the other end means for a slip fit and frictional engagement with said integral part of said opposite face of said adapter, said integral part of said adapter being an integrally molded projection from said adapter, said projection having formed therein cam-like wedging surfaces to sides of an opening thereto and said other end of said shaft device being formed so when disposed in one position to freely pass through said opening and in a second position to lock to said wedging surfaces.

2. Apparatus as set forth in claim 1 characterized by said projection having a cup-like form, said opening being a slot in the base thereof and said other end of said shaft having lateral projections camming into frictional engagement with said wedging surfaces.

3. Apparatus as in claim 2 characterized by said opening being a diametral slot in the base of said cup formed projection and said wedging surfaces being 0pposed oppositely inclined ramps.

4. A device for use in surface grinding, polishing and like operations comprising a thin flexing adapter having on one face a substantially planar operating surface for receiving abrasive means as a cover and, as an integral part of its opposite face, means to mount to a drive medium with a slip friction fit, and abrasive means disposing coextensively of and in fixed relation to said adapter operating surface to free flex therewith and provide a sheet-like form which readily contours to the shape of an applied work piece, said adapter being formed of molded plastic as a single disposable element.

S. A finishing tool, including a back-up member having a front surface receiving a sanding disc or the like in application thereto, a portion of said member to its opposite face being configured to provide a coupling for connection thereof to a driving shaft means, said portion having an opening therein and an inclined ramp on the interior thereof on each side of said opening, said ramps being substantially parallel and oriented reversely of one another to provide on one side of said opening an upwardly sloping surface and on the other side thereof a downwardly sloping surface.

6. A finishing tool as in claim 5 characterized by said portion being a cup-like projection of said member and said opening being a slot in said projection.

7. A tool according to claim 6 characterized by the outer end of said projection being constructed as a transverse wall segment-and said ramps being formed integrally with said wall segment, on an interior surface thereof.

8. A tool according to claim 5 characterized by said member being formed in one piece to include a central cup-like projection forming a recess opening through said front face of said member and the bottom of said recess defining said ramps to either side of said opening which is formed therein.

9. A finishing tool according to claim 5, characterized by an adapter shaft having at one end thereof oppositely projecting pin portions, said one end of said shaft upon being inserted in said opening positioning said pin portions to ride upward on respective ramps in a wedging movement responsive to relative rotation of said shaft and member in one sense.

10. A finishing tool according to claim 9, wherein said adapter shaft is formed with a reactant expanded section longitudinally spaced from said pin portions and drawn to close engagement on the exterior surface of said projection responsive to wedging movement of said pin portions on said ramps.

11. A finishing tool according to claim 9, wherein high portions of said ramps serve as stops engageable by said pin portions to limit relative rotation of said shaft and back-up member in an opposite sense and to align said pin portions with said slot.

12. A device for use in surface grinding, polishing and like operations comprising a thin flexible sheet-like disc presenting a planar operating surface having formed therein a central cavity defined by an integrally connected cup shaped projection extending from the surface of said disc remote from said operating surface, the base portion of said cup projection being displaced from said operating surface and having formed therein cam means for friction lock thereof to a drive medium so as to displace the drive medium from said operating surface, and for quick release thereof from said drive medium as a separable unit, said sheet-like disc, including its said projection, being of molded plastic material and said sheet-like disc being adapted to receive abrasive material in a superposed relation on its said planar operating surface to provide that it be self-sustaining yet full flexing and self conforming to the contour of a work piece to which the same may be applied.

13. A device for use in surface grinding, polishing and like operations comprising a thin flexing disc of sheet-like plastic having on one face thereof a substantially planar operating surface adapted to receive abrasive means coextensive therewith as a cover and said disc having integral with its opposite face an extended cup-shaped projection defining a cavity in the central portion thereof opening from said planar operating surface, the base of said cup being displaced from said planar operating surface, said cup projection being molded integral with the face of said disc opposite said operating surface and its base portion incorporating cam means in integrated relation to provide for a quick release friction coupling thereto of a drive medium for said disc, which is thereby provided as a readily separable, replaceable and disposable device. 

1. A device for use in surface grinding, polishing and like operations comprising a thin flexing adapter having on one face a substantially planar operating surface for receiving abrasive means as a cover and, as an integral part of its opposite face, means to mount to a drive medium with a slip friction fit, and a drive medium in the form of a shaft device having at one end a pin-like form for slip fit to a chuck-like driving head and at the other end means for a slip fit and frictional engagement with said integral part of said opposite face of said adapter, said integral part of said adapter being an integrally molded projection from said adapter, said projection having formed therein cam-like wedging surfaces to sides of an opening thereto and said other end of said shaft device being formed so when disposed in one position to freely pass through said opening and in a second position to lock to said wedging surfaces.
 2. Apparatus as set forth in claim 1 characterized by said projection having a cup-like form, said opening being a slot in the base thereof and said other end of said shaft having lateral projections camming into frictional engagement with said wedging surfaces.
 3. Apparatus as in claim 2 characterized by said opening being a diametral slot in the base of said cup formed projection and said wedging surfaces being opposed oppositely inclined ramps.
 4. A device for use in surface grinding, polishing and like operations comprising a thin flexing adapter having on one face a substantially planar operating surface for receiving abrasive means as a cover and, as an integral part of its opposite face, means to mount to a drive medium with a slip friction fit, and abrasive means disposing coextensively of and in fixed relation to said adapter operating surface to free flex therewith and provide a sheet-like form which readily contours to the shape of an applied work piece, said adapter being formed of molded plastic as a single disposable element.
 5. A finishing tool, including a back-up member having a front surface receiving a sanding disc or the like in application thereto, a portion of said member to its opposite face being configured to provide a coupling for connection thereof to a driving shaft means, said portion having an opening therein and an inclined ramp on the interior thereof on each side of said opening, said ramps being substantially parallel and oriented reversely of one another to provide on one side of said opening an upwardly sloping surface and on the other side thereof a downwardly sloping surface.
 6. A finishing tool as in claim 5 characterized by said portion being a cup-like projection of said member and said opening being a slot in said projection.
 7. A tool according to claim 6 characterized by the outer end of said projection being constructed as a transverse wall segment and said ramps being formed integrally with said wall segment, on an interior surface thereof.
 8. A tool according to claim 5 characterized by said member being formed in one piece to include a central cup-like projection forming a recess opening through said front face of said member and the bottom of said recess defining said ramps to either side of said opening which is formed therein.
 9. A finishing tool according to claim 5, characterized by an adapter shaft having at one end thereof oppositely projecting pin portions, said one end of said shaft upon being inserted in said opening positioning said pin portions to ride upward on respective ramps in a wedging movement responsive to relative rotation of said shaft and member in one sense.
 10. A finishing tool according to claim 9, wherein said adapter shaft is formed with a reactant expanded section longitudinally spaced from said pin portions and drawn to close engagement on the exterior surface of said projection responsive to wedging movement of said pin portions on said ramps.
 11. A finishing tool according to claim 9, wherein high portions of said ramps serve as stops engageable by said pin portions to limit relative rotation of said shaft and back-up member in an opposite sense and to align said pin portions with said slot.
 12. A device for use in surface grinding, polishing and like operations comprising a thin flexible sheet-like disc presenting a planar operating surface having formed therein a central cavity defined by an integrally connected cup shaped projection extending from the surface of said disc remote from said operating surface, the base portion of said cup projection being displaced from said operating surface and having formed therein cam means for friction lock thereof to a drive medium so as to displace the drive medium from said operating surface, and for quick release thereof from said drive medium as a separable unit, said sheet-like disc, including its said projection, being of molded plastic material and said sheet-like disc being adapted to receive abrasive material in a superposed relation on its said planar operating surface to provide that it be self-sustaining yet full flexing and self conforming to the contour of a work piece to which the same may be applied.
 13. A device for use in surface grinding, polishing and like operations comprising a thin flexing disc of sheet-like plastic having on one face thereof a substantially planar operating surface adapted to receive abrasive means coextensive therewith as a cover and said disc having integral with its opposite face an extended cup-shaped projection defining a cavity in the central portion thereof opening from said planar operating surface, the base of said cup being displaced from said planar operating surface, said cup projection being molded integral with the face of said disc opposite said operating surface and its base portion incorporating cam means in integrated relation to provide for a quick release friction coupling thereto of a drive medium for said disc, which is thereby provided as a readily separable, replaceable and disposable device. 